Draftsman&#39;s parallel-line instrument



1 Feb. 1923. HA Sim DRAFTSMANS PARALLEL LINE INSTRUMENT.

FILED APR. 18. I922.

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L T F r W155 INVEN TOR WW sitions.

Patented Feb. 13, 1923.

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a time HARRY $1301, or NEW YORK, niYQ nner'rs'ivrens PARALLEL-LINE.'insrnn vrnur.

. Application filed April 18,

To all whom it may concern.

Be-it known that I, HARRY'SIROT, a citizen of the United States, residing at New York, in thecounty of the Bronx and State of New York, have invented certain new and useful Improvements in Draftsmens Parallel-Line Instruments, of which the following is a specification.

This invention relates to parallel line instruments particularly used in general en gineering practise, the main object being the provision of an instrument which can be removably secured at any location on a drawing board and will permit a series of straight parallel lines to be drawn parallel and adjacent to a guide line, without the necessity of shifting or employing other instruments.

Another object is the provision of a' device as described which essentially comprises a so-called straight edge having a triangle movable thereon so that the latter can be set to ibewith irregular angles and transpose the latter from a drawing to an article of manufacture or vice versa.

These and other objects will become apparent in the description below in which characters of reference refer to the likenamed parts in the drawing.

Referring briefly to the drawing, Figure 1 is a front elevational view of the device showing the triangle thereon in various p0- Figure is an end elevational view ofthe same.

Figure 3 is a fragmentary front elevational view showing the triangle intilted position. I

Figure 4 is a partial cross sectional view thru the device taken on line 1 l of ure 1. I

Figure 5 is a bottom plan view of Figure 3.

Describing the drawing in detail, the numeral 10 indicates a rectangular bar, commonly called a straight edge. having inclined surfaces 11 upon which graduations 12 corresponding to inch measurements are formed. Said bar 10 is provided with a channel 13 extending thruout its length the central portion thereof being enlarged int a semi-circular recessl l. I

A triangle 15 provided with an opening 16 has a, plurality of finger notches 17 formed on the edges of said opening by which the triangle can be lifted from the surface it is placed on. Said triangle has slots 18 and 18 extending parallel to corre- 1922. Serial no. 555,108.

.sponding sides which are joined to each other at their point of1ntersect1on'19 located near one'o'f the vertices. j

A lug20 located centrallyonthe upper surface of bar 10 has ahole therein which loosely receives a stem 21 threaded at the end 22 and provided with a bend 23 at its opposite end. Saidbend extends downwardly into bar 10 thru an enlarged hole 24 and is adapted to engage either of the said slots 18 or 18.

A thumb screw 25 engaging the threaded I end 22 of member 21 shoulders on the side of lug 20 and providesa means'for locking the triangle in any position on the bar 10. I Thumb tacks '26 secured in the ends of the 1 bar 10 project'from the bottom surface and provide a means for holding the instrument in place on a drawing board or other similar surface. 1 i H The instrument, when in use, is placed upon the drawing board in a position where 1t 1s desired to rule or draw a series of par. allel lines. The bar is firmly pressed down:

ward so that the tack points 26 are em bedded in the board. moving the triangle in either direction a series of lines can be drawn parallel to each other. These lines are widely used in a drafting room when indicating sections and is termed cross I cate it. in position for angular parallel lines while the broken lines show one of its sides in'perpendicular alignment. The change is accomplished bysliding the triangle to the I intersection 19 and tilting it or rotating it about said intersection. Figure-.3 shows the triangle being rotated about said intersectionl any of its positions by thumb nut 25.

I claim manipulation of the 1. A device of the class described comprising a bar having a channel formed therein, a triangle slidable in said channel, tacks projecting from saidbar and adapted to removably secure the latter in place,and

means for securely locking said triangle in any position relative to said channel.

Member 23 engaging either of the slots 18 and .18 can secure the triangle in engaging said threaded ste n, a triangle slidable in said channel having inter-communicating slots arranged parallel to its corresponding sides and adapted to receive the downwardly bent portion of said stem, said tlnnnb nut adapted to securely lock the triangle in a desired'position on said bar, said triangle being rotatable on said bent pertions When said thumb nut is in unlocked position and means for securing said device in place on a drawing board or the like.

In Witness whereof I, ailix my signature.

HARE Y SIROT. 

